四种市售色谱级乙腈的质量比较

目的乙腈在近紫外波段只有弱吸收,作为溶剂,乙腈被广泛应用于色谱技术中,色谱纯乙腈的质量直接影响分析方法的灵敏度和准确性。目前,国内销售的乙腈质量参差不齐,本研究旨在比较国内销售4种乙腈的质量差异。方法通过紫外透光率实验、液相梯度淋洗实验以及顶空-气质联用3种实验的结果,比较4种乙腈质量差异,结果紫外透光率实验中,乙腈(Ⅰ)在低紫外吸收处(波长小于210nm)的透光率最高,4种乙腈在波长高于220nm时的透光率接近;在高效液相色谱梯度淋洗实验中,乙腈(Ⅰ)的基线变化最小,乙腈(Ⅳ)其次,乙腈(Ⅱ)与乙腈(Ⅲ)在梯度淋洗过程中出现了杂质峰;在顶空-气质联用实验中,乙腈(Ⅰ)色谱图中未知杂质峰数量最少且总峰面积最小,乙腈(Ⅳ)其次,乙腈(Ⅱ)与乙腈(Ⅲ)在17.5min处的杂质峰较大。结论通过实验比较,国内销售的4种乙腈,乙腈(Ⅰ)的综合质量最好,乙腈(Ⅳ)其次,乙腈(Ⅱ)与乙腈(Ⅲ)再次。本研究可以为国内研究者根据实验目的,合理选用色谱级乙腈提供借鉴。

The aim of this study is to compare the quality of four commercially available acetonitrile(ACN).The results of UV transmittance,liquid phase gradient elution experiments and the application of gas chromatography-mass spectrometry were compared.The results showed that ACN(Ⅰ)has the highest transmittance at lower UV absorption(wavelength less than 210 nm).Above 220 nm,the transmittance of the four ACN is similar;the results of HPLC gradient elution,it can be seen that the baseline change of ACN(Ⅰ)is the smallest,(Ⅳ)second,and(Ⅱ)and(Ⅲ)are in the gradient.A peak appeared during the leaching process;in the gas chromatography-mass spectrometry analysis(GC-MS),ACN(Ⅰ)was the smallest at the unknown impurity peak,(Ⅳ)followed.The impurity peaks in(Ⅱ)and(Ⅲ)at 17.5 min are both large.